Re: [PATCH v4 16/16] slab: Remove references to folios from virt_to_slab()

[Matthew Wilcox <willy@infradead.org>]

On Mon, Nov 24, 2025 at 04:09:32PM +0900, Harry Yoo wrote:
> By the way, there is one remaining code snippet that references folio in
> alloc_from_pcs():
> 
>   if (folio_nid(virt_to_folio(object)) != node)
> 
> which won't work after separating struct slab from struct folio :)

Oh, thank you!  This is a fairly silly thing to do today as there's
an unnecessary use of compound_head() to go from page to folio.
Each page knows which node it belongs to (and that's going to continue
to be true until we get to an 8-byte struct page) so there's no need
to do page_to_memdesc().  It'll be worth it once we do get to an 8 byte
struct page as we'll know what kind of memdesc this is rather than
having page_to_nid() figure it out.

Patch soon.